1080p video smackdown: iTunes vs. Blu-ray

Now that Apple is selling and renting movies and TV shows in 1080p, the …

Ars was recently able to conclude that the newly launched iTunes movies encoded in 1080p do, in fact, look better than the same content encoded in 720p, despite the modest increase in file size. That's good news for iTunes customers. But the real question is: how do iTunes 1080p downloads compare to the reigning king of home video image quality—Blu-ray Disc (BRD)? This is what we set out to test.

Due to hardware and DRM limitations, we were forced to take photos of the screen instead of using screenshots. The screen was the same in both cases: a Dell U2312HM monitor with 1920x1080 resolution, with a MacBook Air connected through the DisplayPort port, and a Panasonic DMP-BD65 Blu-ray player connected using an HDMI-to-DVI cable.

I used the movie 30 Days of Night for the test. According to the Internet Movie Database, this 2007 movie was filmed in the common Super 35 (film) format and then transferred to a 2k digital intermediate; in other words, it was edited in the digital domain.

The iTunes download clocks in at a handsome 3.62GB (where 1GB = 2^30 bytes). It contains a stereo AAC track as well as a Dolby Digital 5.1 track. The video resolution is 1920x798. The BRD is a dual layer BD 50 and has a Dolby Digital 5.1 as well as a DTS-HD track, a number of special features and 30 seconds worth of unskippable copyright warnings.

Things started out well for iTunes with the movie's titles, which look very sharp on both BRD and iTunes 1080p. The images below show the individual pixels. The iTunes image is always on top or to the left, the BRD image on the bottom or to the right.

Text is very sharp in both formats

An early scene that shows a ship on the ice-filled sea also shows that iTunes 1080p almost matches Blu-ray's level of detail. At the top is a screenshot from the MacBook Air, where one pixel on your screen is one pixel from the original image. Below to the left is the iTunes version photographed from the screen, to the right is the BRD version.

The iTunes version (left) is slightly softer

Being a vampire movie that plays in (a fictionalized) Barrow, Alaska during the 30 days in the middle of winter when the sun doesn't rise, this movie isn't exactly filled with strong colors. But when they appear, both the iTunes and BRD versions show them off with equal gusto.

Color reproduction is almost identical

As you can see, these aren't your soulful, brooding vampires. Pay attention to the detail on the bright parts of the nose and the forehead. The BRD retains detail while the iTunes version blows them out.

iTunes (left) has trouble with the highlights

An example of iTunes struggling a bit is this scene where the camera tracks a moving car. The Blu-ray version of the telephone pole close-up shows much more detail—including noise or grain. The trouble with noise is that it's random so it doesn't compress well. This means the stronger iTunes compression needs to get rid of both detail and noise—which are the same thing to a compression algorithm—to hit its compression target. The BRD, on the other hand, can happily reproduce the noise as present in the source, burning up untold megabits and leaving details untouched.

Grain and movement

So far, iTunes has been able to keep up with Blu-ray for the most part. But early in the movie, there is a fade from black to dark clouds. Dark gradients are often a problem area with image compression. So it's no surprise that iTunes stumbles at this point, and shows significant banding. Blu-ray, on the other hand, has no problems. (I made the image brighter because otherwise it would be hard to make out on a white page.)

iTunes (top) shows significant banding

What can we conclude from this?

I was surprised to see how close the iTunes 1080p download comes to Blu-ray, considering that it's only a fraction of the file size. And let's be honest: there are lots of Blu-ray titles that look much worse than this iTunes download. But despite an impressive effort by Apple, Blu-ray still reigns king when it comes to image quality. And unlike iTunes titles, BRDs can have uncompressed multi-channel audio, multiple audio language options, and special features. Am I being greedy in wanting both good-looking downloads for convenience, as well as buy-once-play-anywhere Blu-ray discs of my all-time favorite movies?

This article needs a follow-up with a more definitive study that asks "can 10 people tell the difference between Blu-ray and iTunes 1080p?" Use 10 second clips of a variety of different scenes and report back results!

Obviously BR will be better. The question is if the iTunes (or any downloadable media format), is just "good enough". MP3s have replaced the CD, not because they are of better quality, but because they are easy and good enough.

I just really hope that BlueRays don't disappear because if you really like a movie of high quality, it's better to get a hard copy.

"Am I being greedy in wanting both good-looking downloads for convenience, as well as buy-once-play-anywhere Blu-ray discs of my all-time favorite movies?"

Not remotely, if anything there should be more flexibility and features on the download version to justify you basically paying to ship it. Online movies are convenient and I love stuff like all-you-can-eat LoveFilm but actually owning an optical disc seems much better value if you're into a movie.

I want a 40 days of night sequel though. Sarah Palin Vampire? You betcha!

One thing that's being missed with this comparison between iTunes and physical media is that Apple has already shown that it will upgrade titles purchased previously (720p to 1080p). In a few years, Apple could decide to upgrade the quality of their 1080p clips -- or move us to an even higher resolution to take advantage of whatever displays they are selling by then. But all of our BluRay discs will still be where they are today and will require us to purchase new copies of the same movies again to get the better quality.

Apple's model was always portrayed as a purchase model where the user gets to continue using whatever media they purchase forever. But it's appearing that it's really more than that -- it's a one time payment for the rights to use and download whatever is the current best format that Apple provides.

As much as it enrages videophiles, it appears as if streaming/downloaded video has finally reached the "good enough" level of quality for most people. In fact, unless the masses take effort to become OCD over picture quality, they might not even be able to discern the difference.

Now if only Hollywood would decide to stop dragging its feet on licensing and pricing.

One thing that's being missed with this comparison between iTunes and physical media is that Apple has already shown that it will upgrade titles purchased previously (720p to 1080p). In a few years, Apple could decide to upgrade the quality of their 1080p clips -- or move us to an even higher resolution to take advantage of whatever displays they are selling by then. But all of our BluRay discs will still be where they are today and will require us to purchase new copies of the same movies again to get the better quality.

Apple's model was always portrayed as a purchase model where the user gets to continue using whatever media they purchase forever. But it's appearing that it's really more than that -- it's a one time payment for the rights to use and download whatever is the current best format that Apple provides.

In this area, iTunes clearly wins over BluRay, IMO.

Do you honestly believe that this will happen? That the movie industry will allow that to happen?

I've moved to 100% digital movie purchases on iTunes. The quality is good enough, it's very easy to use, and I don't have to have a lot of crappy plastic boxes lying around my apt everywhere. Plus, I can play them on my computer, TV, phone, and tablet. What's not to like?

Great comparison. Overall it looks like the itunes 1080p video is adequate assuming they're not attempting to charge the same price for rental/ownership as a BRD.

In some cases it costs more to "own" a movie on iTunes than it does on Blu-ray. But to be fair to Apple I don't think they have as much control over the pricing as they would like. Studios would rather not cannibalize their tried and true physical formats for a digital format under someone else's control.

I would much rather buy a movie on Blu-ray (wait a couple months and you'll find them for $10) and rip it myself if I feel that I need a digital copy. Of course that means finding the space for the discs but what with the new Kindle my bookshelves were looking pretty barren anyway.

ebbv wrote:

The Ugly wrote:

How many un-skippable trailers, advertisements, and copyright notices does the iTunes copy of the movie "feature"?

Every Blu Ray disc I've owned so far the stuff is skippable but it's not always obvious how. Some discs you have to hit the "Next Section" button to skip the trailers, sometimes it's the Menu button.

It's obnoxious but I have yet to run into one where there's actually *no way* to skip.

Being able to skip from one forced movie trailer to the next in a line of six forced movie trailers is not the same as them being totally skippable. When I watch a movie I want to be able to hit root menu to get past it all in one press and watch the movie I paid for. Having to hit the "next track" button ten times to get to the menu that lets me begin a film is complete BS. But Lions Gate is the only studio I know of that does that on Blu-ray discs and I am not sure if they're still doing it on newer titles. It probably also depends on the player you use. A lot of older DVD players were made to force you to watch all the warnings and trailers up front but newer ones were able to skip all of that.

One thing that's being missed with this comparison between iTunes and physical media is that Apple has already shown that it will upgrade titles purchased previously (720p to 1080p). In a few years, Apple could decide to upgrade the quality of their 1080p clips -- or move us to an even higher resolution to take advantage of whatever displays they are selling by then. But all of our BluRay discs will still be where they are today and will require us to purchase new copies of the same movies again to get the better quality.

Apple's model was always portrayed as a purchase model where the user gets to continue using whatever media they purchase forever. But it's appearing that it's really more than that -- it's a one time payment for the rights to use and download whatever is the current best format that Apple provides.

In this area, iTunes clearly wins over BluRay, IMO.

Don't count your chickens before they're hatched.

Just because they've done something you consider good up until now doesn't mean they'll always do it.

Unfortunately, most people have a screen that's way too small to see the detail at the viewing distance they use. From what I've seen, in the homes of my friends, many of whom are audio and videophiles, they can't tell the difference between 720 and 1080 from where they sit, and a few can't even get a true 720 from their seating position.

I've got a 61" screen, but I also sit too far away, about 12'. I would need a 103" diagonal size screen to see 1080 in full resolution. The truth is that none of the comparisons made here have any validity for the large majority of people.

I have to say...I'm more impressed than I thought I'd be. My wife and I cut the cord after doing the math and figuring out it was cheaper to buy seasons on iTunes than pa or cable for a year. We bought a couple of movies but this is what I've been waiting for...except for a few must haves on Blu-ray, I think ee'll be getting our movies here. I'll bet this is the quality tipping point for most consumers.

I'm becoming increasingly disenchanted with Ars tendency to declare absolute results from rather unscientific experiments. (Especially as these results will inevitably get re-reported and trotted out to support arguments they may not, in fact, conclusively support all over the Internet.)

While perhaps not invalidating the conclusions in itself, the use of further lossy compression (jpeg) on screenshots/photographs intended to capture the (in)efficiencies and differences of two lossily compressed sources is symptomatic of the issue.

I do wish these were direct screenshots, instead of photos of a monitor. As much as I'd like to poo-poo streaming media, I must admit, the only thing that would drive me nuts here is the banding. When it comes to watching visually arresting movies, I can live with some slightly blown highlights and very minor detail reduction, but banding is a no-go for me.

Do you honestly believe that this will happen? That the movie industry will allow that to happen?

They've already allowed it once -- 720p to 1080p. I don't know if it will happen again, but it's certainly more plausible than all of our BluRay discs getting magically upgraded.

As you can see from the comments the upgrade capability for the iTunes moves is a moot point. If the general public can't tell the difference now what makes you think anybody will be able to in the future. 3D will be the next mountain to clime.

If the resolution is 1920x798, then wouldn't the video be 798p or maybe 1080i? Also, besides gradients, compression usually causes macro-blocking in fast motion scenes. Did you notice any of this during the faster moving scenes in the iTunes video clips?

Still shots of film or video never tells a true story. If anyone has ever seen a still from any film, they would see how bad they look. This was my business for decades. We always had problems with it. The eye and brain integrates movement in a way that has us ignoring much of what the stills are showing. When I had to make stills from a movie frame, no matter how the frame was produced, the still was always disappointing. It was unsharp, noisy, blown out, etc. we just don't notice it when watching the film, unless we're programming ourselves to do so, as you are.

The only useful comparisons, other than for technical work, are short sequences viewed together, as we used to have to do. Even then, it could be difficult. A slight change in the playback adjustments would often wipe out much, or all of the differences, or even make the poorer copy look better. Stand back a couple of feet, and all differences due to sharpness, grain, and often, Ben banding goes away.

So unless you're anal enough to bring your chair too close to the screen for comfort, or fortunate enough to have a big enough screen, little of this will matter.

Pfft, I went to the Metropolitan Opera last year. Now if they can beat THAT resolution, I'd be impressed.

bhahahahahaa....oh....oh I hurt my side....

But yeah, slowly and slowly we'll get to the point to where we can buy movies or TV shows and watch them on devices of our choice....which is how we have music now. But remember, even that took a while.

Iljitsch van Beijnum / Iljitsch is a contributing writer at Ars Technica, where he contributes articles about network protocols as well as Apple topics. He is currently finishing his Ph.D work at the telematics department at Universidad Carlos III de Madrid (UC3M) in Spain.